The price column is the fourth column from the left. Colours are user-definable but in this case we have:
Last Traded Price – Black on Grey
Price Traded This Session – White on Light Grey.
Price Not Traded This Session – White on Dark Black.
At a glance we can see that we last traded 112'035 and that 112'070 is the high of the day.
The centre line is the white line between 112'035 and 112'040. Again, this is optional. When you Left click the centre button 
this line will be painted in above the inside bid after centering. This is useful in correlated markets. If you are showing DOM for correlated markets, you can centre the DOMs and then you will be able to see at a glance if one market is moving ahead after you re-centred them.
Right click on the centre button will center all windows.